g++ pushbutton.cpp -I$QTDIR/include -I$QTDIR/lib -lqt
 이렇게 하면여..
 /usr/bin/ld: cannot find -lqt
collect2: ld returned 1 exit status
 이런 에러만 나여..ㅜ.ㅜ
 QTDIR path도 맞는데..;;